Perez gets first start at designated hitter

CHICAGO -- With Salvador Perez locked in during a career-long 12-game hitting streak, Royals manager Ned Yost couldn't justify keeping his young catcher out of the lineup on Saturday.

So, with Brayan Pena scheduled to catch left-hander Bruce Chen, Yost inserted Perez in the designated-hitter slot for the middle contest of the Royals' three-game series against the White Sox.

Regular DH Billy Butler shifted to first base in place of Eric Hosmer, who is 1-for-9 in his career against White Sox starter Chris Sale.

Saturday marked Perez's first career start anywhere other than catcher. A handful of factors made Perez finally serving as the designated hitter possible:

 The Royals have three catchers on their roster, thanks to September callups.

 Hosmer's struggles against Sale.

 Perez is on fire, batting .360 (18-for-50) during his hitting streak.

The disadvantage of Saturday's lineup, of course, is having Butler at first base instead of Hosmer. Butler started at first on Tuesday and committed an error in the third, when he missed a throw from shortstop Alcides Escobar. But Yost said he wasn't concerned.

"I've seen Billy play first base a lot, and that doesn't happen very often," Yost said. "The tough picks, Hosmer's going to make. But Billy [is fine]."

Royals' lack of walks doesn't worry Yost

CHICAGO -- The Royals received four free passes in Friday night's win against the White Sox, thanks mostly to Chicago lefty Francisco Liriano showing some inconsistency.

It was the third time in the last six games the Royals have drawn four walks -- although in the other three games, they've only combined to draw one.

Kansas City's lack of patience is nothing new, with the Royals dead last in the Majors with only 345 walks this season. Royals manager Ned Yost said he isn't concerned about the lack of plate discipline, saying he believes it will grow with time.

"You just can't come in here and demand plate discipline from a young hitter," Yost said. "It's a process. We talk about it, sure. We talk about it a lot, but [our players] will continue to grow and get more disciplined as their careers go on."

Yost continues to push young bullpen

CHICAGO -- The Royals continue to work their bullpen hard, especially the top four relievers.

Why shouldn't they? The four-man group of Tim Collins, Kelvin Herrera, Aaron Crow and Greg Holland has been quite impressive.

"I really feel like on a given day I can protect a one-run lead from the sixth inning on with those guys," Royals manager Ned Yost said.

The problem is, Yost did it on Friday in Chicago. The quartet also threw in Thursday's series finale against Texas, but Yost said all will be available on Saturday, too. The skipper knows he can't keep pounding them every day, but also said there are no health concerns with any of them.

As teams across baseball shut down young arms in the season's final month, Yost said there's no such plan for his bullpen crew. Collins (22 years old), Herrera (22), Crow (25) and Holland (26) are all in their first or second full Major League seasons.

"Like any manager, you worry about their health and giving them too much of a workload early. But we are into September," Yost said. "It's all part of them learning how to pitch into September, too, in big games. So yeah, there's going to be times where you're going to be a little fatigued. So what? You've got to get after it."

Yost said getting the experience of pitching in September is key for a young pitcher's maturation. During his nine-year managerial career, Yost has heard pitchers complain about arm soreness late in the season.

"And then they realize, 'Hey, I can pitch through that and I can pitch through that effectively,'" Yost said.

It's those types of experiences that Yost believes help young pitchers in the long run.

"You have to experience [a season] from the first day of Spring Training until Oct. 3," Yost said. "When you've been going hard, and you've had high-anxiety innings and you come into games like Herrera did [Friday] night with the game on the line ... it takes a lot [out] of you.

"But when you're battling for a championship -- the whole August, September and going into October, it's going to be like that. You've got to learn what it feels like, you've go to learn that, 'Hey, I can get through this.'"

Omaha grabs series lead

The victory, which gaves the Storm Chasers a 2-1 lead in the best-of-five series, came after a two-hour, three-minute rain delay. The game didn't finish until 12:41 a.m. MT on Saturday.

Seratelli homered and Max Ramirez knocked a two-run single in the top of the third. Maier's two-run shot in the seventh put the Storm Chasers ahead, 5-0, and they added one more in both of the final two innings.

The Isotopes scored once in the seventh and added three in the eighth before Omaha's Roman Colon walked one in a scoreless ninth to earn the save.

Crown points

 The Royals' current six-game winning streak against the White Sox is tied for the longest in franchise history.

The Royals previously won six straight against the White Sox in 1982, and also won six in a row against Chicago during a two-season stretch from 1972-73.

 Chen entered Saturday one strikeout shy of 1,000 for his career.

Cash Kruth is a reporter for MLB.com. Follow him on Twitter at @cashkruth. This story was not subject to the approval of Major League Baseball or its clubs.